兰州地铁1号线黄河隧道盾构施工难点及应对措施研究

兰州地铁黄河隧道为国内首条交通工程类下穿黄河隧道,地质条件极为独特。为解决盾构连续性长距离在大粒径高压富水弱胶结高硬度的砂卵石地层中如何安全顺利掘进下穿黄河,采用理论分析与现场施工反馈紧密结合的方法,研究盾构下穿黄河施工难点及应对措施。研究表明:土压盾构在穿黄施工中相继遇到刀盘卡机、刀具磨损、螺旋机喷涌、固结泥饼、地面塌陷等问题;泥水盾构相继遇到掘进困难、卵石积仓滞排堵管、破碎机故障频发、刀盘刀具管路磨损、泥浆击穿河床等问题,通过设备改造,优化掘进参数,做好区间降水、工法辅助、泥浆制配、渣土改良、刀具改进、气压稳定等工作,有效解决盾构在砂卵石地层中掘进的相关问题,确保黄河隧道顺利建成。

The Difficulties and Countermeasures in Shield Construction of Yellow River Tunnel of Lanzhou Metro Line-1

Yellow River tunnel of Lanzhou metro is the first traffic engineering tunnel passing under Yellow River with unique and extreme geological conditions. To ensure safe,continuous,smooth and long distance excavation in the ground with large diameter,high pressure,rich water,weak cementation,high hardness sand and gravel strata under the Yellow river,theoretical analysis and site construction feedback are employed to identify the difficulties and measures for shield driving under the Yellow River. The research results show that the EPB meets with such problems as cutter stuck,cutlery abrasion,spiral conveyer spewing, mud consolidation, ground collapse and so on; the SPB encounters excavation difficulty,sandy pebble accumulation and blocking,frequent crusher failure,cutter head and pipe abrasion,riverbed breakdown by slurry and so on. Through targeted equipment reconstruction,driving parameter optimization,section dewatering,auxiliary construction method,slurry preparation,muck and cutlery improvement,and air pressure stabilization,problems related to shield driving in sand and gravel strata are solved and successful construction of the Yellow River tunnel is guaranteed.